It is known that a Lipopolysaccharide (LPS) is a glycolipid existing in an outer membrane of Gram-negative bacterium and activates a macrophage to induce an expression of many genes. Known examples of such genes having expressions that are induced by the LPS are those of interleukin (IL)-1, exhibiting an antitumor function or an inflammatory function, such as a function to cause an inflammation by a bacterial infection, IL-6, IL-12, IL-15, IL-18, a tumor necrosis factor (TNF), or a chemokine (such as IL-8 or MCP); granulocyte colony-stimulating factor (G-CSF) exhibiting a hemapoietic function, monocyte (M)-CSF, or GM-CSF; or collagenase playing a main role in an inflammation such as that caused by a bacterial infection, cyclooxygenase (COX), or a nitrogen oxide synthase (iNOS) or the like. Almost all of the above proteins encoded by the above genes are physiologically active proteins playing important roles in a body [Annu. Rev. lmmunol., 2, 283-318 (1984); Inflammation: Basic Principles and Clinical Correlates, 637-662, Raven Press Ltd., New York (1992)].
There are about 0.1 million genes in the human chromosome, but only 10 or 20 percentage thereof have been isolated and identified. Therefore, as almost all of the genes have not been isolated or analyzed, it is believed that almost all of the genes having an expression that is specifically induced by LPS are unidentified novel genes.
Septicemia is a systemic disease wherein a festering lesion exists in a body, and many bacteria are intermittently or continuously introduced into the blood from the festering lesion. A diagnosis of the septicemia is carried out by culturing the blood, and when the existence of bacteria is proved, the illness is definitely diagnosed as the septicemia. However, the above method has disadvantages, namely, the method is time-consuming, and when a blood sample is drawn, it may be contaminated with bacteria from skin, such as Staphylococcus epidermidis. 
Therefore, the inventors of the present invention made an intensive search for genes having an expression that is induced specifically at a macrophage by an LPS-stimulation, for the purpose of an application for developing a new method of diagnosis and/or medicament for treating a disease such as inflammation, allergy, or cancer, particularly a bacterial infection. As a result, three novel genes were isolated and identified. Further, the present inventors found that these three genes were not expressed in healthy persons, but were expressed in patients suffering from a bacterial infection. The invention is based on the above findings.